Hand disinfectant

ABSTRACT

The invention concerns a hand disinfectant based on lower alcohols and is characterized by an aqueous solution of lower alcohols with synergists, the solution having a flash point of more than 21° C.

Hand disinfectants containing one or more lower alcohols, such asethanol, isopropanol or n-propanol, are widely known. As a rule, theyare aqueous solutions with an alcohol content of 70 to 80 weight %, andoptionally other compounds that have microbicidal action are added.These known hand disinfectants meet the requirements, formulated byDGHM, for the germicidal effect against bacteria, includingmycobacteria, and fungi.

Increasingly, the viral effectiveness of hand disinfectants based onalcohol has lately been discussed. Their virus inactivation,particularly against highly resistant types of virus, such as polio,does not meet all demands; for instance, it is known that polio virusesfor instance can be inactivated only with a very high percentage ofethanol, and so the usual concentration of between about 70 and 80weight % is not adequate for this purpose. Hence hand disinfectantsbased on 90 to 95 weight % ethanol are already on the market. Althoughthese disinfectants meet the demands for virus inactivation made by theDVV, they have some decisive disadvantages. The most importantdisadvantage is that the flash point of such mixtures with a highethanol content is below 21° C., which makes the preparations subject tothe Code on Flammable Liquids in hazard class B1, and specialregulations must be obeyed regarding shipping, storage, bottling, andthe like. This is a particular burden for hospitals and large medicalpractices, because large quantities of disinfectants are needed, and ingeneral the supply rooms of the applicable institution are not set upfor storing relatively large quantities of flammable liquids. Anotherdisadvantage is that disinfectants with such a high alcohol content,when used for disinfecting hands, dry the skin to an extraordinarydegree, with all the attendant, well-known side effects.

There is therefore still an urgent need for hand disinfectants with goodvirus inactivation effectiveness even for known resistant types ofvirus, but which do not come under hazard class B1 of the Code onFlammable Liquids and which moreover are readily tolerated.

To attain this object, hand disinfectants on the basis of lower alcoholsare proposed, which are characterized in that they contain loweralcohols together with synergists in an aqueous solution and have aflash point above 21° C.

Surprisingly, it has been found that instead of the previouslyconventional high-percentage ethanol solutions for viricidal handdisinfection, preparations that have a substantially lower alcoholcontent in the form of lower alcohols can also be used, if they containmixtures of synergists that promote the viricidal action or virusinactivation of the alcohols, and hence mixtures can be prepared thatare no longer in hazard class B1 of the Code on Flammable Liquids. Thosewhose use is preferred are the lower alcohols, that is, ethanol,isopropanol or n-propanol, which in high concentration have flash pointsbelow 21° C., but which are preferably used in such an aqueous solutionthat the total alcohol content is between about 50 and 60 volume %.

To increase the viricidal or virus-inactivating action, diols are used,specifically preferably those with a chain length of from 3 to 5 carbonatoms. Propanediols are especially suitable, and both positionalisomers, that is, 1,2-propanediol and 1,3-propanediol can be used.1,2-Propanediol is considered safe, although recent studies haveindicated that the toxicity may be somewhat higher than in the1,2-isomer. Along with the propanediols, butanediols can also beconsidered, and specifically all the positional isomers, but1,3-butanediol is preferred, because the most toxicological data isavailable for it.

The diols have a certain bacteriostatic action, and moreover they areused in the foods industry against fungi, for example, and especiallyagainst yeasts. The concentration of the diols may be low and rangesfrom about 3 to about 10 volume Besides the diols, other additives canalso be considered, specifically hydrogen peroxide in a 1 to 3%concentration and sodium alkane sulfonates (E30), that is, essentiallysecondary sulfonic acids with a chain length of the alkyl group ofbetween about 12 and 18 carbon atoms. Alkane sulfonates areenvironmentally tolerable anionic surfactants which exhibit a strongvirus-inactivating effect. The concentration of the alkane sulfonates isin the range frog about 0.2 to about 0.7 weight %.

The substance known as sodium rhodanide, NaSCN, is another highlyeffective synergistic compound. It is indeed known that thiocyanic acidand its salts are microbicidally effective, but so far this activity hashardly been utilized for disinfecting purposes. The concentration ofrhodanide should be between about 1 and 3 weight %.

The mixtures according to the invention are adjusted to be acidic, whichcan be done by adding physiologically safe organic acids that are easyon the skin, in a concentration of about 0.001 to 0.005 mole %.Preferably, citric acid, tartaric acid, malonic acid or malic acid isused, because these acids have no odor of their own. However, othertoxigologically unobjectionable acids may also be used, such as lacticacid, acetic acid, formic acid or propionic acid, and similar compounds.

The mixtures according to the invention have flash points above 21° C.and are therefore not subject to the more-stringent requirements made ofsubstances in hazard class B1. They are markedly easier on the skin thanpreparations with a very high content of alcohols, because drying of theskin does not ensue to the same degree as with high-alcohol solutions.Their effectiveness against bacteria, yeasts and fungi meets theregulations of the DVV or of BIFAM. But in terms of virus-inactivatingeffectiveness, they also meet the requirements of the DGHM.

The preparation of the disinfectants of the invention is done in amanner known per se, by dissolving the usually solid organic acids andby dissolving the synergistically active compounds, such as alkanesulfonates or rhodanide, in some of the total amount of water needed,mixing the liquid alcohols, and adding the total amount of water needed.

The invention will be described in further detail below in terms of theExamples:

EXAMPLE 1

6 l of 96% ethanol are mixed with 500 ml of 1,2-propanediol and 500 mlof 1,3-butanediol and mixed carefully. Into this mixture, an aqueoussolution of 200 ml of 1-molar citric acid is worked in, and the mixtureis then diluted with 2.8 l of double-distilled water. The flash point,determined in accordance with DIN 51755, is 22.5° C.

EXAMPLE 2

6 l of 96% ethanol, as indicated in Example 1, are mixed with 500 ml of1,2-propanediol and 500 ml of 1,3-butanediol and 200 ml of a 1-molartartaric acid solution and diluted with 2.8 l of distilled water. Theflash point, determined in accordance with DIN 51755, is 23.0° C.

EXAMPLE 3

As described in Example 1, 6 l of 96% ethanol, 1 l of 1,2-propanediol, 1l of 1,3-butanediol and 200 ml of a 1-molar citric acid are mixed andwater is added to make up 10 l.

EXAMPLE 4

6 l of 96% ethanol, 3 l of 1,2-propanediol, and 200 ml of 1-molar malicacid are mixed and water is added to make up 10 l.

EXAMPLE 5

6 l of 96% ethanol are mixed with 1 l n-propanol, 500 ml of1,2-propanediol and 500 ml of 1,3-butanediol and mixed carefully. Intothis mixture, an aqueous solution of 200 ml of 1-molar citric acid isworked in, and the solution is then diluted with 1.8 l ofdouble-distilled water.

The flash point, determined in accordance with DIN 51755, is 22° C.

EXAMPLE 6

6 l of 96% ethanol are mixed with 500 ml n-propanol, 500 ml ofisopropanol, 500 ml of 1,2-propanediol and 500 ml of 1,3-butanediol andmixed. Into this mixture, 200 ml of a 1-molar malic acid solution isthen worked in, and the solution is then diluted with 1.8 l ofdouble-distilled water.

The flash point, determined in accordance with DIN 51755, is 21.5° C.

EXAMPLE 7

6 l of 96% ethanol are mixed with 200 ml n-propanol, 700 ml isopropanol,500 ml of 1,2-propanediol and 500 ml of 1,3-butanediol and mixed. Intothis mixture, 200 ml of 1-molar citric acid is then worked in, and thesolution is then diluted with 1.9 l of double-distilled water.

The flash point, determined in accordance with DIN 51755, is 21° C.

We claim:
 1. A hand disinfectant based on lower alcohols which comprisesan aqueous solution of lower alcohols along with one or more diols andone or more synergists selected from the group consisting of hydrogenperoxide, alkane sulfonates and salts of thiocyanic acid, saiddisinfectant having a flash point above 21° C.
 2. The hand disinfectantof claim 1 which contains ethanol.
 3. The hand disinfectant of claim 2which has an ethanol content between about 50 and about 60 volume %. 4.The hand disinfectant of claim 3 which has an ethanol content of about57 volume %.
 5. The hand disinfectant of claim 1 which containspropanediol.
 6. The hand disinfectant of claim 1 which containsbutanediol.
 7. The hand disinfectant of claim 1 which contains1,2-propanediol.
 8. The hand disinfectant of claim 1 which contains1,3-butanediol.
 9. The hand disinfectant of claim 1 which containsapproximately 5-10 volume % diols, 1-3 weight % hydrogen peroxide orsalts of thiocyanic acid, and/or 0.2 to 0.7 weight % alkane sulfonates.10. The hand disinfectant of claim 1 which contains at least onephysiologically safe organic acid.
 11. The hand disinfectant of claim 1which contains between about 0.01 and 0.05 mole % organic acids.